USN-4916-1: Linux kernel vulnerabilities
=========================================================================
Ubuntu Security Notice USN-4916-1
April 15, 2021
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15,
linux-dell300x, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm,
linux-lts-xenial, linux-oracle, linux-raspi2, linux-snapdragon
vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems
- linux-dell300x: Linux kernel for Dell 300x platforms
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm: Linux kernel for cloud environments
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-raspi2: Linux kernel for Raspberry Pi (V8) systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty
Details:
It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges. (CVE-2021-3493)
Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 18.04 LTS:
linux-image-4.15.0-1017-dell300x 4.15.0-1017.21
linux-image-4.15.0-1070-oracle 4.15.0-1070.78
linux-image-4.15.0-1084-raspi2 4.15.0-1084.89
linux-image-4.15.0-1090-kvm 4.15.0-1090.92
linux-image-4.15.0-1098-gcp 4.15.0-1098.111
linux-image-4.15.0-1099-aws 4.15.0-1099.106
linux-image-4.15.0-1101-snapdragon 4.15.0-1101.110
linux-image-4.15.0-1113-azure 4.15.0-1113.126
linux-image-4.15.0-142-generic 4.15.0-142.146
linux-image-4.15.0-142-generic-lpae 4.15.0-142.146
linux-image-4.15.0-142-lowlatency 4.15.0-142.146
linux-image-aws-lts-18.04 4.15.0.1099.102
linux-image-azure-lts-18.04 4.15.0.1113.86
linux-image-dell300x 4.15.0.1017.19
linux-image-gcp-lts-18.04 4.15.0.1098.116
linux-image-generic 4.15.0.142.129
linux-image-generic-lpae 4.15.0.142.129
linux-image-kvm 4.15.0.1090.86
linux-image-lowlatency 4.15.0.142.129
linux-image-oracle-lts-18.04 4.15.0.1070.80
linux-image-powerpc-e500mc 4.15.0.142.129
linux-image-powerpc-smp 4.15.0.142.129
linux-image-powerpc64-emb 4.15.0.142.129
linux-image-powerpc64-smp 4.15.0.142.129
linux-image-raspi2 4.15.0.1084.81
linux-image-snapdragon 4.15.0.1101.104
linux-image-virtual 4.15.0.142.129
Ubuntu 16.04 LTS:
linux-image-4.15.0-1070-oracle 4.15.0-1070.78~16.04.1
linux-image-4.15.0-1098-gcp 4.15.0-1098.111~16.04.1
linux-image-4.15.0-1099-aws 4.15.0-1099.106~16.04.1
linux-image-4.15.0-1113-azure 4.15.0-1113.126~16.04.1
linux-image-4.15.0-142-generic 4.15.0-142.146~16.04.1
linux-image-4.15.0-142-generic-lpae 4.15.0-142.146~16.04.1
linux-image-4.15.0-142-lowlatency 4.15.0-142.146~16.04.1
linux-image-4.4.0-1092-kvm 4.4.0-1092.101
linux-image-4.4.0-1127-aws 4.4.0-1127.141
linux-image-4.4.0-1151-raspi2 4.4.0-1151.162
linux-image-4.4.0-1155-snapdragon 4.4.0-1155.165
linux-image-4.4.0-209-generic 4.4.0-209.241
linux-image-4.4.0-209-generic-lpae 4.4.0-209.241
linux-image-4.4.0-209-lowlatency 4.4.0-209.241
linux-image-4.4.0-209-powerpc-e500mc 4.4.0-209.241
linux-image-4.4.0-209-powerpc-smp 4.4.0-209.241
linux-image-4.4.0-209-powerpc64-emb 4.4.0-209.241
linux-image-4.4.0-209-powerpc64-smp 4.4.0-209.241
linux-image-aws 4.4.0.1127.132
linux-image-aws-hwe 4.15.0.1099.92
linux-image-azure 4.15.0.1113.104
linux-image-gcp 4.15.0.1098.99
linux-image-generic 4.4.0.209.215
linux-image-generic-hwe-16.04 4.15.0.142.137
linux-image-generic-lpae 4.4.0.209.215
linux-image-generic-lpae-hwe-16.04 4.15.0.142.137
linux-image-gke 4.15.0.1098.99
linux-image-kvm 4.4.0.1092.90
linux-image-lowlatency 4.4.0.209.215
linux-image-lowlatency-hwe-16.04 4.15.0.142.137
linux-image-oem 4.15.0.142.137
linux-image-oracle 4.15.0.1070.58
linux-image-powerpc-e500mc 4.4.0.209.215
linux-image-powerpc-smp 4.4.0.209.215
linux-image-powerpc64-emb 4.4.0.209.215
linux-image-powerpc64-smp 4.4.0.209.215
linux-image-raspi2 4.4.0.1151.151
linux-image-snapdragon 4.4.0.1155.147
linux-image-virtual 4.4.0.209.215
linux-image-virtual-hwe-16.04 4.15.0.142.137
Ubuntu 14.04 ESM:
linux-image-4.15.0-1113-azure 4.15.0-1113.126~14.04.1
linux-image-4.4.0-1091-aws 4.4.0-1091.95
linux-image-4.4.0-209-generic 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-generic-lpae 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-lowlatency 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-powerpc-e500mc 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-powerpc-smp 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-powerpc64-emb 4.4.0-209.241~14.04.1
linux-image-4.4.0-209-powerpc64-smp 4.4.0-209.241~14.04.1
linux-image-aws 4.4.0.1091.88
linux-image-azure 4.15.0.1113.86
linux-image-generic-lpae-lts-xenial 4.4.0.209.182
linux-image-generic-lts-xenial 4.4.0.209.182
linux-image-lowlatency-lts-xenial 4.4.0.209.182
linux-image-powerpc-e500mc-lts-xenial 4.4.0.209.182
linux-image-powerpc-smp-lts-xenial 4.4.0.209.182
linux-image-powerpc64-emb-lts-xenial 4.4.0.209.182
linux-image-powerpc64-smp-lts-xenial 4.4.0.209.182
linux-image-virtual-lts-xenial 4.4.0.209.182
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References:
https://ubuntu.com/security/notices/USN-4916-1
CVE-2021-29154, CVE-2021-3493
Package Information:
https://launchpad.net/ubuntu/+source/linux/4.15.0-142.146
https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1099.106
https://launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1113.126
https://launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1017.21
https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1098.111
https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1090.92
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1070.78
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1084.89
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1101.110
https://launchpad.net/ubuntu/+source/linux/4.4.0-209.241
https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1127.141
https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1099.106~16.04.1
https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1113.126~16.04.1
https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1098.111~16.04.1
https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-142.146~16.04.1
https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1092.101
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1070.78~16.04.1
https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1151.162
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1155.165
A Linux kernel security update has been released for Ubuntu Linux 14.04 ESM, 16.04 LTS, and 18.04 LTS.
